JP7186575B2 - Cooling system and battery structure - Google Patents

Description

The present invention relates to cooling devices and battery structures.

A battery block is constructed by, for example, arranging a plurality of battery cells and fixing them to a support member, and electrically connecting the positive and negative terminals of each battery cell to each other by a bus bar or the like. A battery module, for example, includes a plurality of such battery blocks, and has a structure in which the plurality of battery blocks are stacked vertically or arranged in parallel and fixed to a base member.
Battery blocks and battery modules are mounted as power sources in, for example, electric vehicles and hybrid vehicles, and are capable of outputting large currents. Each battery cell forming a battery block generates heat during charging and discharging. For this reason, such battery blocks are sometimes provided with a cooling device. As an example of such a battery block cooling device, a first plate having a mounting surface in thermal contact with the corresponding assembled battery, a second plate fixed to a surface opposite to the mounting surface, A cooling mechanism including a cooling channel formed between both plates is known (for example, Patent Document 1).

WO2017/002325

However, the cooling mechanism disclosed in Patent Literature 1 has a problem of increased weight because both the first plate and the second plate are made of metal. Furthermore, when applied to cooling large or heavy battery blocks, the seals between the metal plates are partially destroyed by shock or vibration, and if the cooling medium leaks and contacts the assembled battery, the battery will short-circuit. I was afraid.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a cooling device that can reduce the risk of leakage of a cooling medium and is excellent in light weight.

According to the present invention, the following cooling device and battery structure are provided.
[1]
a resin plate made of a light-transmitting resin member (A) and having a plurality of grooves;
a metal plate provided on the surface of the resin plate on which the groove is formed,
At least part of the resin plate and the metal plate are joined via an intermediate layer made of a light-absorbing resin member (B),
The cooling device, wherein the groove portion of the resin plate forms a coolant flow path.
[2]
The cooling device according to the above [1], wherein at least the peripheral portion of the resin plate and the metal plate are joined via the intermediate layer.
[3]
The cooling device according to the above [1] or [2], wherein the intermediate layer and the resin plate are welded together.
[4]
The cooling device according to any one of [1] to [3], wherein the metal plate and the intermediate layer are joined by injection molding.
[5]
The cooling device according to any one of the above [1] to [4], wherein the metal plate has a fine concavo-convex structure formed on the joint surface with the intermediate layer.
[6]
The light-absorbing resin member (B) contains a light-absorbing agent,
The cooling device according to any one of [1] to [5] above, wherein the content of the light absorbing agent in the light absorbing resin member (B) is 0.01% by mass or more and 5% by mass or less.
[7]
The cooling device according to any one of the above [1] to [6], wherein outer peripheral ends of the resin plate and the metal plate are riveted or screwed.
[8]
Any one of the above [1] to [7], wherein the metal plate is composed of at least one member selected from the group consisting of an aluminum member, an aluminum alloy member, a copper member and a copper alloy member. The cooling device according to .
[9]
Any one of the above [1] to [8], wherein one end of the coolant channel formed by the groove formed in the resin plate is connected to the injection pipe and the other is connected to the discharge pipe. 1. Cooling device according to 1.
[10]
The above [1] to [9], wherein the cooling device is for cooling a battery block in which two or more battery cells are laid flat and are closely attached to each other or adjacent to each other with a certain interval. ] The cooling device according to any one of .
[11]
The cooling device according to any one of [1] to [9] above, wherein the cooling device is a cold plate for cooling electronic components.
[12]
a battery block in which two or more battery cells are arranged on a flat surface so as to be in close contact with each other or adjacent to each other with a certain interval;
The cooling device according to any one of [1] to [10] above;
a case accommodating the battery block;
with
A battery structure in which the battery block is arranged on the metal plate in the cooling device.
[13]
The battery structure according to [12] above, wherein the battery cell is a lithium ion battery.

ADVANTAGE OF THE INVENTION According to this invention, the cooling device which can reduce the risk of leakage of a cooling medium and is excellent in lightness can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is the perspective view which showed typically an example of the structure of the cooling device which concerns on this embodiment. FIG. 2 is a cross-sectional perspective view in the yz direction passing through point A of the cooling device shown in FIG. 1; FIG. 3 is a cross-sectional view conceptually showing an example of the layer arrangement of metal plate-intermediate layer-resin plate (cross-sectional view of FIG. 2 viewed from the S direction). FIG. 4 is a perspective view schematically showing an example of a method of laser welding a resin plate; 1 is a perspective view schematically showing the structure of a test piece for airtightness evaluation (helium leak test); FIG. 6 is a cross-sectional perspective view of the test piece shown in FIG. 5 cut along yy'; FIG. 1 is a perspective view schematically showing the structure of a test piece for measuring tensile shear strength; FIG. It is sectional drawing which showed the example (a) and (b) which arrange|positioned a battery cell on the cooling device which concerns on this embodiment. Note that grooves (channels) in the resin plate are not shown. FIG. 11 is a diagram showing an enlarged photograph of a contacting portion of both members after a tensile test in Example 4;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, in all the drawings, the same constituent elements are denoted by the same reference numerals, and the explanation thereof is omitted as appropriate. Moreover, the drawings are schematic diagrams showing an example of the present invention, and do not correspond to actual dimensional ratios. Unless otherwise specified, "~" between numbers in the text indicates the following from the above.

<Cooling device>
The cooling device 1 according to the present embodiment includes a resin plate 2 made of a light-transmitting resin member (A) and having a plurality of grooves 24 formed therein, and a surface of the resin plate 2 having the grooves 24 formed thereon. At least a portion of the resin plate 2 (for example, the skirt portion 23) and the metal plate 4 are connected via the intermediate layer 3 made of the light-absorbing resin member (B). It is a cooling device in which the grooves 24 of the resin plate 2 form flow paths for the cooling medium (see FIGS. 1 and 2). Here, from the viewpoint of further reducing the risk of refrigerant leakage from the cooling device 1, it is preferable that at least the peripheral edge portion of the resin plate 2 and the metal plate 4 are bonded via the intermediate layer 3. More preferably, the skirt portion 23 of the resin plate 2 and the metal plate 4 are joined via the intermediate layer 3 .
Since the entire metal plate 4 is cooled by a cooling medium (hereinafter abbreviated as a coolant) that flows through the flow paths formed in the resin plate 2, the battery cells and electronic components that are in contact with the metal plate 4 are cooled. It is possible to increase the cooling efficiency of the heat generating element such as. In addition, since the flow paths (grooves 24) of the coolant are integrally formed of the same material as the lightweight resin plate 2, the weight of the entire cooling device 1 can be reduced.
That is, according to this embodiment, weight reduction is achieved by replacing a part of the plate with a resin member, and the risk of refrigerant leakage can be suppressed by increasing the airtightness between the metal member and the resin member. A cooling device for cooling heat generating bodies such as battery cells and electronic components can be provided.

FIG. 3 is a cross-sectional view conceptually showing an example of arrangement and bonding of the skirt portion 23 of the resin plate 2, the intermediate layer 3, and the metal plate 4 that constitute the cooling device 1 according to this embodiment. It is preferable that the resin plate 2 (for example, the skirt portion 23 that is the peripheral portion of the resin plate 2) and the intermediate layer 3 are welded by laser or the like. An example of a laser irradiation path for laser welding is shown as a dashed line in FIG. 4, but the irradiation path in this embodiment is not limited to this irradiation path.
In addition, in the cooling device 1 according to the present embodiment, from the viewpoint of further reducing the risk of refrigerant leakage from the cooling device 1, at least the joint surface of the metal plate 4 with the intermediate layer 3 has a fine uneven structure. is preferably formed. Further, the intermediate layer 3 and the metal plate 4 according to the present embodiment have a fine concave-convex structure formed at least on the joint surface with the intermediate layer 3 in the metal plate 4, and the light that constitutes the intermediate layer 3 It is preferred that the absorbent member (B) is joined by injection molding. As a result, the risk of coolant leakage from the cooling device can be minimized.

Hereinafter, the resin plate 2, the intermediate layer 3, and the metal plate 4 that constitute the cooling device 1 will be sequentially described, and then an example of a method of manufacturing the cooling device 1 from these constituent elements will be described.

(Resin plate 2)
The resin plate 2 according to this embodiment is made of a light-transmitting resin member (A), preferably a molded body of a light-transmitting thermoplastic resin composition. In the present embodiment, the light-transmitting property of the light-transmitting resin member (A) is not particularly limited as long as it has a degree of light-transmitting property that allows laser to pass through and reach the intermediate layer 3. For example, , the transmittance of a specimen having a thickness of 1 mm at a wavelength of 940 nm is preferably 25% or more, more preferably 30% or more.
The light-transmitting thermoplastic resin composition contains a thermoplastic resin (a) as a resin component, and may further contain additives as necessary.

The thermoplastic resin (a) is not particularly limited. Polystyrene resin, polyvinyl alcohol-polyvinyl chloride copolymer resin, polyvinyl acetal resin, polyvinyl butyral resin, polyvinyl formal resin, polymethylpentene resin, maleic anhydride-styrene copolymer resin, polycarbonate resin, polyphenylene ether resin, polyether Aromatic polyether ketone such as ether ketone resin, polyether ketone resin, polyester resin, polyamide resin, polyamideimide resin, polyimide resin, polyetherimide resin, styrene elastomer, polyolefin elastomer, polyurethane elastomer, polyester Elastomer, polyamide elastomer, ionomer, aminopolyacrylamide resin, isobutylene maleic anhydride copolymer, ABS, ACS, AES, AS, ASA, MBS, ethylene-vinyl chloride copolymer, ethylene-vinyl acetate copolymer, ethylene-vinyl acetate-vinyl chloride Graft polymer, ethylene-vinyl alcohol copolymer, chlorinated polyvinyl chloride resin, chlorinated polyethylene resin, chlorinated polypropylene resin, carboxyvinyl polymer, ketone resin, amorphous copolyester resin, norbornene resin, fluoroplastic, polytetrafluoroethylene Resin, fluorinated ethylene polypropylene resin, PFA, polychlorofluoroethylene resin, ethylene tetrafluoroethylene copolymer, polyvinylidene fluoride resin, polyvinyl fluoride resin, polyarylate resin, thermoplastic polyimide resin, polyvinylidene chloride resin, polyvinyl chloride resin , polyvinyl acetate resin, polysulfone resin, polyparamethylstyrene resin, polyallylamine resin, polyvinyl ether resin, polyphenylene oxide resin, polyphenylene sulfide (PPS) resin, polymethylpentene resin, oligoester acrylate, xylene resin, maleic acid resin, Polyhydroxybutyrate resin, polysulfone resin, polylactic acid resin, polyglutamic acid resin, polycaprolactone resin, polyethersulfone resin, polyacrylonitrile resin, styrene-acrylonitrile copolymer resin, etc. be These thermoplastic resins may be used singly or in combination of two or more.

Among these, as the thermoplastic resin (a), the adhesive strength and airtightness between the resin plate 2 and the intermediate layer 3 can be further enhanced, so polyolefin resins, polyester resins, polyamide resins, and fluorine resins can be used. One or two or more thermoplastic resins selected from resins, polyarylene ether-based resins and polyarylene sulfide-based resins are preferably used.

In the thermoplastic resin composition according to the present embodiment, a filler as an optional additive component can be used in combination from the viewpoint of improving the mechanical properties of the resin plate 2 and adjusting the linear expansion coefficient difference. As the filler, for example, one or more can be selected from the group consisting of glass fiber, carbon fiber, carbon particles, clay, talc, silica, minerals and cellulose fiber. Among these, one or more selected from glass fiber, carbon fiber, talc, and minerals are preferred. A heat-dissipating filler typified by alumina, forsterite, mica, alumina nitride, boron nitride, zinc oxide, magnesium oxide, and the like can also be used. The shape of these fillers is not particularly limited, and may be any shape such as fibrous, particulate, or plate-like. If so, it is preferable to use a filler that is large enough to enter the recess.

When the thermoplastic resin composition contains a filler, the content thereof is preferably 1 part by mass or more and 100 parts by mass or less, more preferably 5 parts by mass or more and 90 parts by mass with respect to 100 parts by mass of the thermoplastic resin. It is not more than 10 parts by mass, and particularly preferably 10 parts by mass or more and 80 parts by mass or less. If the content of the filler is equal to or less than the above upper limit, scattering and reflection of laser light can be suppressed during laser welding, which will be described later, and as a result, the efficiency of laser welding can be improved.

As a method for molding the resin plate 2, known methods can be used without limitation, such as injection molding, extrusion molding, hot press molding, compression molding, transfer molding, cast molding, laser welding molding, reaction injection molding (RIM molding). ), rim molding (LIM molding), thermal spray molding, and the like. Among these methods, the injection molding method is preferable as the method for manufacturing the resin plate 2 from the viewpoint of productivity and quality stability.

A plurality of grooves 24 are formed on one surface of the resin plate 2 on the side of the metal plate 4 according to the present embodiment, and the grooves 24 are formed on the entire surface on the side of the metal plate 4. preferable. The groove 24 functions as a coolant flow path by coming into close contact with the surface of the metal plate 4 . Normally, the tops of the plurality of grooves 24 are set at the same height, and all or part of the tops are configured to be in contact with the surface of the metal plate 4 . Inside the resin plate 2, if necessary, one or more reinforcing resin bosses or reinforcing struts having the same height as the top of the groove 24 are provided within a range that does not hinder the smooth flow of the refrigerant. may An inlet tube connection port 21 and an outlet tube connection port 22 are provided at the inlet and outlet of the channel (that is, the ends of the channel). That is, one end of the coolant channel formed by the grooves 24 formed in the resin plate 2 according to the present embodiment is connected to the injection pipe, and the other end is connected to the discharge pipe.
A manifold part is provided in the channel as required.

Reinforcing ribs may be formed on the surface of the resin plate 2 according to the present embodiment opposite to the surface on the metal plate 4 side. By forming the reinforcing ribs, the structural strength of the resin plate 2 is increased against external stress, and by setting the rib height high, a sufficient space is created between the resin plate 2 and the contact surface. , the heat insulation effect may be improved.

(Intermediate layer 3)
In the cooling device 1 according to this embodiment, it is preferable that the resin plate 2 is welded to the intermediate layer 3 and that the intermediate layer 3 is joined to the metal plate 4 . That is, the intermediate layer 3 is a layer interposed between the resin plate 2 and the metal plate 4 . The intermediate layer 3 is made of a light-absorbing resin member (B). The thermoplastic resin (b) constituting the light-absorbing resin member (B) is, for example, the same thermoplastic resin as the thermoplastic resin (a) constituting the light-transmitting resin member (A). or all of them may be different resin species.

The thickness of the intermediate layer 3 is, for example, 0.1 mm or more and 10 mm or less, preferably 0.2 mm or more and 5 mm or less. If the thickness is at least the above lower limit, heat radiation control of the absorbed energy of the laser beam becomes easier when the resin plate 2 and the intermediate layer 3 are laser-welded, and the occurrence of deformation of the intermediate layer 3 can be suppressed. Therefore, it is preferable. When the thickness of the intermediate layer is equal to or less than the above upper limit value, sink marks are less likely to occur during injection molding, so that the flatness of the top surface of the intermediate layer 3 that is the welding surface with the resin plate 2 can be improved. When the intermediate layer 3 has a top surface with good flatness, for example, when the top surface of the intermediate layer 3 and the planar portion of the skirt portion of the resin plate face each other and are laser-welded, the generation of gaps can be suppressed. , welding can proceed more effectively.

In this embodiment, the light transmittance of the intermediate layer 3 having a thickness of 1 mm at a wavelength of 940 nm is preferably 10% or less, more preferably 5% or less.
Such a property of being difficult to transmit light can be exhibited by, for example, incorporating a light absorbing agent such as a coloring pigment or a dye into the thermoplastic resin (b). Examples of coloring pigments include black pigments such as carbon black, red pigments such as iron oxide red, white pigments such as titanium oxide, and various organic pigments. Among them, inorganic pigments generally have strong hiding power and can be preferably used. Two or more of these color pigments may be used in combination.

As the light absorbing agent, a laser light absorbing dye having an absorption wavelength within the wavelength range of the irradiated laser light can also be used.
Laser light absorbing dyes include, for example, nigrosine, aniline black, phthalocyanine, naphthalocyanine, porphyrin, perylene, quaterrylene, azo dyes, anthraquinone, squaric acid derivatives, immonium and the like.

A particularly preferred laser light-absorbing dye among these is nigrosine. Nigrosine is a black azine-based condensation mixture. Such nigrosine can be synthesized, for example, by subjecting aniline, aniline hydrochloride and nitrobenzene to oxidation and dehydration condensation at a reaction temperature of 160 to 180° C. in the presence of iron chloride. Commercially available products of nigrosine include, for example, "NUBIAN (registered trademark) BLACK" (trade name, manufactured by Orient Chemical Industry Co., Ltd.).

When the light-absorbing resin member (B) contains a light-absorbing agent, the content of the light-absorbing agent in the light-absorbing resin member (B) is 0 when the entire light-absorbing resin member is 100% by mass. 0.01 to 5% by mass, more preferably 0.1 to 4% by mass, even more preferably 0.2 to 3% by mass. Among these light absorbing agents, carbon black is most preferably used.

(Metal plate 4)
The metal plate 4 that constitutes the cooling device 1 according to the present embodiment diffuses heat from a heating element such as a lithium-ion battery and efficiently transfers heat to the coolant that flows through the resin plate 2. play two roles. Therefore, it is preferable that the metal species forming the metal plate 4 have excellent heat conductivity. From such a point of view, aluminum or copper is used as the metal species constituting the metal plate 4. Specifically, it is selected from the group consisting of an aluminum member, an aluminum alloy member, a copper member, and a copper alloy member. It is preferable to be configured by at least one member that Also, the average thickness of the metal plate 4 is, for example, 0.5 mm to 30 mm, preferably 0.5 mm to 20 mm, taking heat transfer, strength and lightness into consideration.

At least the joint surface of the metal plate 4 with the intermediate layer 3 is preferably degreased. In addition, it is more preferable that a fine uneven structure is formed or a hydrophilic group is formed on at least the joint surface of the metal plate 4 with the intermediate layer 3, and the surface on which the fine uneven structure is formed Furthermore, it is more preferable that a hydrophilic group is formed. By doing so, the bonding strength between the intermediate layer 3 and the metal plate 4 can be increased, and as a result, leakage of the refrigerant can be further suppressed, and more excellent cooling can be achieved due to the reliability of mechanical strength and durability. A device 1 can be obtained.

In the preferred form (first form) of the present embodiment, the profile (depth, hole diameter, hole-span distance, etc.) of the fine uneven structure formed on the joint surface of the metal plate 4 at least with the intermediate layer 3 is Although there is no particular limitation, the average height measured in a cross-sectional photograph of an electron microscope to be described later, or the average height measured according to JIS B 0601, or the ten-point average roughness Rzjis is, for example, 1 nm or more, preferably is 3 nm or more and 1 mm or less, more preferably 5 nm or more and 100 μm or less. The fine concavo-convex structure may consist of a plurality of different sizes. As such an example, for example, a nano-sized ultra-fine uneven structure having an average height of 1 nm to 300 nm is formed on a large micron-sized fine uneven structure having a ten-point average roughness of 1 μm to 100 μm. profile.

Although there is no particular limitation on the method for imparting such a fine uneven structure to the surface of the metal plate 4, for example, an inorganic base aqueous solution such as sodium hydroxide and/or an inorganic acid aqueous solution such as hydrochloric acid or nitric acid is added to the metal member. A method of treating a metal member by an anodizing method; A metal member surface by pressing a mold punch having unevenness made by mechanical cutting, such as diamond abrasive grinding or blasting, onto the metal member surface A method of forming unevenness, a method of creating unevenness on the surface of a metal member by sandblasting, knurling, or laser processing; A method of immersing a metal member in an aqueous solution of one or more kinds selected from amine compounds can be used.

Among the above-described methods, when the method of immersing in a chemical bath is employed, the entire metal plate 4 may be immersed, or the surface on which the fine uneven structure is not desired to be formed is masked with a masking tape. It can be immersed. In the former case, on the metal plate 4, not only the joint surface of the intermediate layer 3 but also the entire surface of the metal plate 4 is formed with a fine uneven structure. It does not impair the effect of form in any way.

In another preferred form (second form) of the present embodiment, specific examples of the hydrophilic group covering at least the joint surface of the metal plate 4 with the intermediate layer 3 include a hydroxyl group and a silanol group. The introduction of hydrophilic groups such as hydroxyl groups to the metal surface can be achieved, for example, by carrying out a plasma surface modification technology that appropriately combines Open Air (trademark) and Plasma Plus (trademark) technologies developed by Plasmatreat. be. In addition, introduction of silanol groups to the metal surface can be achieved by itro treatment (silicicification flame treatment) as described in Japanese Patent No. 3557194, for example. In order to further introduce a hydroxyl group or a silanol group to the metal surface on which the fine uneven structure is formed, once the fine vomiting shape is formed on the metal surface by the above method, plasma or Itro treatment may be further performed.

<Manufacturing Method of Cooling Device 1>
In the cooling device 1 according to the present embodiment, for example, the banks of the intermediate layer 3 are formed on the metal plate 4 by injection molding, and then the periphery of the separately molded resin plate 2 is formed on the intermediate layer 3 (banks). ), for example, by welding using a laser or the like. Injection molding and welding will be described below.

(injection molding)
First, a mold for injection molding is prepared, the mold is opened, and the metal plate 4 is placed on a part of the mold. After that, the mold is closed, and the light-absorbing thermoplastic resin composition is injected so that at least part of the light-absorbing thermoplastic resin composition is in contact with the area on which the fine unevenness is formed on the surface of the metal plate 4. The intermediate layer 3 is formed by molding and solidifying. After that, the mold is opened and released to obtain the metal plate 4 on which the intermediate layer 3 (bank portion) is formed.

In injection molding, injection foam molding and high-speed heat cycle molding (RHCM, heat & cool molding) in which the mold is rapidly heated and cooled may be used together.
Methods of injection foam molding include, for example, a method of adding a chemical foaming agent to the resin; a method of injecting nitrogen gas or carbon dioxide gas directly into the cylinder of an injection molding machine; injection molding of nitrogen gas or carbon dioxide gas in a supercritical state. There is a MuCell injection foam molding method of injecting into the cylinder part of the machine. In any method, it is also possible to use a counter pressure as a method of controlling the mold, or use a core back depending on the shape of the molded product.

(welding)
As a method of welding the resin plate 2 to the intermediate layer 3, for example, laser welding may be used.
FIG. 4 is a perspective view schematically showing an example of a method of laser welding the resin plate 2. As shown in FIG. As shown in FIG. 4, for example, after the skirt portion 23 formed on the peripheral portion of the resin plate 2 is superimposed on the top surface of the intermediate layer 3 (bank portion), the pressurized state is maintained as necessary. The resin plate 2 can be welded to the intermediate layer 3 by irradiating the laser beam while the resin plate 2 is in contact with the intermediate layer 3 . It is preferable to press both surfaces to be welded at the time of laser welding. When applying pressure, the pressure is usually 0.5 to 10 MPa, preferably about 1 to 50 MPa, although it depends on the laser irradiation conditions. By applying a pressure of 0.5 MPa or more, a close contact state can be produced between the welding plane of the intermediate layer 3 and the welding plane of the resin plate 2 at the time of laser welding, so that efficient laser welding becomes possible.

In the cooling device 1 according to this embodiment, in addition to the fact that the resin plate 2 and the metal plate 4 are welded and joined via the intermediate layer 3 as described above, at least the resin plate 2 and the metal plate It is preferable that the outer peripheral edge of the plate 4 and the plate 4 are fastened together by mechanical fitting means such as rivets or screws, with or without the intermediate layer 3 interposed therebetween. By firmly joining and mechanically fastening the resin plate 2 and the metal plate 4 in two stages in this manner, the leakage of the coolant flowing through the resin plate 2 can be suppressed more effectively.

<Battery structure>
An embodiment of a battery block and a battery structure according to this embodiment will be described below with reference to the drawings.
In the battery structure according to the present embodiment, for example, as schematically shown in FIG. 8, two or more battery cells 101 are arranged so that the flat surfaces thereof are upright and adhered to each other or adjacent to each other at a certain interval. It includes the arranged battery blocks, the cooling device 1 according to the present embodiment, and a case 105 that houses the battery blocks, and the cooling device 1 has a metal plate 4 on the opposite side of the mounting surface of the resin plate 2. A battery block is placed on the surface. Note that FIG. 8 does not show the grooves (coolant flow paths) formed in the resin plate.
That is, the cooling device 1 according to the present embodiment is used to cool a battery block in which two or more battery cells are laid flat and are closely attached to each other or adjacent to each other with a certain interval.
Examples of the shape of the battery cell 101 include a rectangular shape, a cylindrical shape, and a pouch shape.

The battery block according to the present embodiment includes a plurality of battery cells 101 (see FIG. 8), a pair of side plates (not shown) for fixing the plurality of battery cells 101 arranged in a predetermined direction, and a battery cell It is preferable to have a pair of end plates (not shown) respectively arranged at both ends in the arrangement direction of 101 . Also, the cooling device 1 preferably extends in the direction in which the plurality of battery cells 101 are arranged. One battery block or a plurality of battery blocks is preferably covered with, for example, a box-shaped or U-shaped metal case 105 to provide waterproof, dustproof, and shockproof functions.

The battery cell 101 is, for example, a lithium ion battery such as a lithium ion secondary battery. Each battery cell 101 has a power generation unit (not shown) housed in a battery can made of a metal member such as aluminum, filled with a non-aqueous electrolyte, and sealed.

A spacer 102 fixed to the metal plate 4 may be interposed between each battery cell 101 . That is, spacers 102 (cooling fins) may be formed on the side of the metal plate 4 opposite to the side of the resin plate 2 . When the spacer 102 is not interposed (see FIG. 8A), it is preferable that the battery cells are arranged so that a gap is generated between the adjacent battery cells. This is because air cooling becomes possible due to the existence of the gap. In the battery structure according to this embodiment, spacers 102 made of an insulating material are usually interposed between the cells (see FIG. 8(b)). Particularly in the case of a pouch-shaped battery cell, spacers 102 are preferably interposed to reinforce the weakness of the cell when the cell is upright. Each spacer 102 may have openings into which the battery cells 101 are inserted on both sides in the thickness direction (battery cell arrangement direction), and a partition wall may be formed in the middle.

In the battery structure according to this embodiment, the spacers 102 may also function as cooling fins by being integrated with the metal plate 4 . In this case, spacers 102 (cooling fins) are generally made of the same material as that of metal plate 4, and more specifically aluminum alloy and copper alloy can be exemplified as preferred examples. A thermally conductive sheet may be attached to the surfaces of the cooling fins in contact with the battery cells 101 as necessary. The end plate is formed, for example, by integrally molding an aluminum alloy formed by aluminum die casting or the like, a highly rigid resin, or a resin and a steel plate.

In this embodiment, a thermally conductive sheet is preferably interposed between the metal plate 4 that constitutes the cooling device 1 and the bottom surface of each battery cell 101 . Normally, the number of thermally conductive sheets and battery cells 101 is the same. In other words, it is preferable that the heat conductive sheet and the battery cell 101 are arranged at a ratio of 1:1. With this structure, even if unevenness exists in the height direction (Z direction) of the lower surface of each battery cell 101, heat conduction between each battery cell 101 and the cooling device 1 can be improved. can.

However, if the thermally conductive sheet is a strip-shaped member that is 1:1 with the battery cell 101, the insulation resistance may be lowered. On the other hand, if no spacers or cooling fins are placed on the metal plate 4 (see FIG. 8(a)), a single thermally conductive sheet is placed to cover the entire area of the bottom surface of the battery cell. structure. If all the lower surfaces of battery cells 101 are substantially flat, only one thermally conductive sheet can be accommodated. Substances called so-called thermal interface materials (TIM) may be used in place of the thermally conductive sheet, specifically thermal grease, phase change material (PCM), gel, high thermal conductive adhesive, thermal tape, etc. can be exemplified.

<Other Applications of Cooling Device>
The cooling device according to this embodiment is applied as a cooling device for various heating elements other than the aforementioned battery block. A representative example of such a heating element is an electronic component such as a CPU on a system board. The cooling device according to this embodiment can also be used without limitation as a cold plate for such a heating element.

Although the embodiments of the present invention have been described above, these are examples of the present invention and include various configurations other than those described above.

EXAMPLES The embodiments of the present invention will be described below with reference to Examples, but the present embodiments are not limited to these. In addition, the physical-property evaluation method is as follows.
Analysis method of fine uneven structure on metal plate surface, tensile shear strength measurement method of fused body of light-transmitting resin member and light-absorbing resin member, and airtightness evaluation of light-absorbing resin member / metal composite The test method is described.

(Micro uneven structure on metal plate surface)
·Average height A method of measuring the average roughness on the surface of the metal plate 4 on which the fine uneven structure is formed using an electron microscope will be described. This measurement method is applied to ultra-fine relief structures with an average roughness of less than 500 nm. Note that the average height represents the average value of the heights of adjacent peaks and valleys (that is, the distance from the bottom of the valley to the top of the peak). In this embodiment, measurements were made using a laser microscope (VK-X100 manufactured by KEYENCE) or a scanning electron microscope (JSM-6701F manufactured by JEOL). In addition, when obtaining the average height from a photograph taken with a scanning electron microscope or a laser microscope, specifically, the cross section of the fine uneven structure on the surface layer of the metal plate 4 is photographed, and from the obtained photograph, 50 arbitrarily adjacent irregularities are selected, and the distance from the bottom of the valley to the top of the mountain is measured. The sum of all the distances from the bottom of the valley to the top of the mountain and divided by 50 was taken as the average height.

・Ten-point average roughness (Rzjis)
Using a surface roughness measuring device "Surfcom 1400D (manufactured by Tokyo Seimitsu Co., Ltd.)", ten-point average roughness (Rzjis) measured according to JIS B0601 (corresponding to ISO4287) was measured. In addition, the measurement conditions are as follows.
・Radius of stylus tip: 5 μm
・Reference length: 0.8mm
・Evaluation length: 4mm
・Measurement speed: 0.06mm/sec
The measurement was performed for a total of 6 linear portions on the surface of the metal member, consisting of 3 arbitrary parallel linear portions and 3 arbitrary linear portions orthogonal to the linear portions, and the average value was obtained.

(Tensile shear test)
A tensile tester "Model 1323 (manufactured by Aikoh Engineering Co., Ltd.)" was used, and a special jig was attached to the tensile tester. Then, a test piece for tensile shear strength measurement having the dimensions shown in FIG. 7 was measured. The bonding strength was estimated by observing the fracture surfaces of both members after the tensile test with a magnifying glass.

(Airtightness evaluation test)
To evaluate the airtightness of the light-absorbing resin member/metal member composite, the helium leak rate was measured using a helium leak detector. As a helium leak detector, M-212LD manufactured by Canon Anerva Technics was used. FIG. 5 shows the shape of a test piece for airtightness evaluation (Type D.2.2 specimen) defined in ISO19095-2, and FIG. 6 shows its diagonal cross-sectional shape. As will be described later, this test piece is made by injecting a light-absorbing member into a rectangular metal flat plate (50 mm × 50 mm × 2 mm) having a hole of 20 mm in diameter, thereby bonding a resin member around the hole ( See Figure 6). In addition, in order to ensure the airtightness of the O-ring (packing) provided in the gap between the helium leak detector test jig (test port flange surface) and the test piece, a non-etched area is provided on the peripheral edge of the metal surface of the test piece. It is A masking tape (masking tape product name 854 manufactured by 3M Japan) was used to leave a part of the metal surface that was not etched.

A test piece in which no helium leak is observed within 1 minute after helium gas is pressurized (0.1 MPa) (specifically, the helium leak amount of a blank sample within 1 minute after pressurization (5.5 × 10 ^-7 Pa·m ³ /sec)) is evaluated as ○, and a test piece in which helium leak is observed (specifically, a blank sample within 1 minute after pressurization) The test piece in which the increase from the amount of helium leaked from ) exceeds 10%) was evaluated as x.

[Preparation Example 1 of surface-treated metal member]
Masking tape (manufactured by 3M Japan) on both sides of the aluminum plate (50 mm x 50 mm x 2 mm, with a hole of 20 mm diameter in the center) with alloy number 5052 specified in JIS H4000, leaving the hole peripheral portion (edge width 5 mm) masking tape product name 854) was attached. After degreasing the aluminum plate, it is immersed for 3 minutes in a treatment bath 1 filled with an alkaline etching agent (30° C.) containing 15% by mass of sodium hydroxide and 3% by mass of zinc oxide (in the following description, " After that, it was immersed in 30% by mass nitric acid (30° C.) for 1 minute, and the alkaline etchant treatment was repeated once more. Next, the obtained aluminum alloy plate was treated with an acidic etching aqueous solution containing 3.9% by mass of ferric chloride, 0.2% by mass of cupric chloride, and 4.1% by mass of sulfuric acid. It was immersed in the filled treatment bath 2 at 30° C. for 5 minutes and shaken (in the following description, this may be abbreviated as “acid-based etchant treatment”). Next, the surface-treated aluminum alloy plate (m-1) was obtained by performing ultrasonic cleaning (in water for 1 minute) with running water, then drying, and then peeling off the masking tape.

The treated surface of the obtained surface-treated aluminum alloy plate (m-1) is measured using a surface roughness measuring device "Surfcom 1400D (manufactured by Tokyo Seimitsu Co., Ltd.)" in accordance with JIS B0601 (corresponding to ISO4287). Ten-point average roughness (Rzjis) was measured among the surface roughnesses measured. As a result, the Rzjis average value was 19 μm.

[Preparation Example 2 of surface-treated metal member]
The same aluminum alloy plate as the aluminum alloy plate used in Preparation Example 1 of the surface-treated metal member was immersed in a 5% by mass aluminum hydroxide aqueous solution at a temperature of 40° C. for 90 seconds (alkali etching). Next, the aluminum alloy plate was immersed for 2 minutes in a 1 mass % sulfuric acid aqueous solution at 40° C. (acid treatment).

Next, 1,3,5-triazine-2,4,6-trithiol monosodium as a triazinethiol derivative was dissolved in water to a concentration of 0.003% by mass, and 98% by mass of this aqueous solution was added. % concentrated sulfuric acid to a concentration of 2.3% by mass to prepare an aqueous electrolyte solution.
Next, the aqueous electrolyte solution was put into the electrodeposition bath, and the temperature of the aqueous electrolyte solution was adjusted to 60°C. In this aqueous electrolyte solution, the aluminum alloy plate that had been subjected to the alkali etching and the acid treatment, and the plate-like platinum member were immersed. Next, by using the aluminum alloy plate as an anode and the platinum member as a cathode, a voltage of 2.6 V is applied between both electrodes for 60 minutes, so that the surface of the aluminum alloy plate contains alumina as a main component and a triazine thiol derivative. An anodized film was formed (electrodeposition step).
Next, in order to remove the excess aqueous electrolyte solution remaining on the aluminum alloy member, it was washed with hot water (washing process), dried by air blow (temperature 70°C, 5 minutes), and then the masking tape was peeled off. to obtain a surface-treated aluminum alloy plate (m-2).

When the cross-sectional SEM measurement of the treated surface of the obtained surface-treated aluminum alloy plate (m-2) was performed with a scanning electron microscope (JSM-6701F manufactured by JEOL), it had dendrites with an average height of about 200 nm. An ultrafine uneven structure was observed.

[Example 1]
A surface-treated aluminum alloy plate (m-1) is placed in a small dumbbell metal insert mold attached to J55AD-30H manufactured by Japan Steel Works, Ltd., and then a thermoplastic resin composition ( As P), polyphenylene sulfide resin (PPS) manufactured by Tosoh Corporation (brand name: SUSTEEL BGX-545, 45 masses of inorganic filler such as GF), cylinder temperature 270 ° C., mold temperature 160 ° C., primary injection pressure 95 MPa, holding pressure Injection molding was performed under conditions of 80 MPa to obtain an aluminum alloy/PPS composite structure. When the airtightness evaluation test described above was performed on the obtained aluminum alloy/PPS composite structure, no increase in the amount of helium leakage was observed for 1 minute after helium gas pressurization (0.1 MPa), and the evaluation was ◯. .

[Example 2]
The same operation as in Example 1 was performed except that the surface-treated aluminum alloy plate (m-2) was used instead of the surface-treated aluminum alloy plate (m-1). The airtightness evaluation test was evaluated as ◯.

[Example 3]
Instead of Tosoh polyphenylene sulfide resin (PPS), Mitsui Chemicals polyamide (brand name: Arlen A335) and EMS-CHEMIE AG polyamide (brand name: GRIVORY G16) 10: 2 (mass ratio) dry blend Exactly the same operation as in Example 2 was carried out, except that injection molding was performed using a cylinder temperature of 335° C., a mold temperature of 160° C., and a holding pressure of 90 MPa. The airtightness evaluation test was evaluated as ◯.

[Example 4]
A plate 61 made of a light-absorbing resin member having the dimensions shown in FIG. body, light transmittance of wavelength 940 nm; 1%) is placed, and then the end face of the same plate 61 is a light-transmitting resin member (polyamide manufactured by Mitsui Chemicals, brand name Arlen A335, Transmittance of light at a wavelength of 940 nm; 43%) was set from above so as to overlap the end face of the plate 62, and then a quartz glass plate with a thickness of 20 mm was slowly lowered from above while maintaining a horizontal state. Pressurized to and held. A semiconductor laser (wavelength: 940 nm) was irradiated from the direction of the plate 62 through the quartz glass surface in the longitudinal direction of the overlapped surface of the plates 61 and 62 . The laser irradiation conditions were focal diameter of 2 mmφ, laser output of 80 W, and laser scanning speed of 30 mm/sec.
After laser irradiation, the test piece with the end faces overlapping each other is subjected to a tensile tester, model 1323 (manufactured by Aikoh Engineering Co., Ltd.), and a special jig containing the test piece is attached to the tensile tester, Tensile measurement was performed at room temperature (23° C.) under the conditions of a distance between chucks of 60 mm and a tensile speed of 10 mm/min. As a result of observing the fractured surface with a magnifying glass, it was observed that a part of the plate 61 made of the light-absorbing resin member was broken and adhered to the plate 62 made of the light-transmitting resin member (see FIG. 9).

REFERENCE SIGNS LIST 1 cooling device 2 resin plate 21 injection pipe connection port 22 discharge pipe connection port 23 skirt portion 24 groove portion (flow path)
3 Intermediate layer 4 Metal plate 41 Micro uneven structure 50 Test piece for airtightness evaluation 51 Light-absorbing resin member constituting the same test piece 52 Metal member constituting the same test piece 60 Test piece for tensile shear strength measurement 61 Light-absorbing resin member constituting the same test piece 62 Light-transmitting resin member constituting the same test piece 101 Battery cell 102 Spacer (cooling fin)
105 cases

Claims (13)

a resin plate made of a light-transmitting resin member (A) and having a plurality of grooves;
a metal plate provided on the surface of the resin plate on which the groove is formed,
At least a part of the resin plate and the metal plate are joined via an intermediate layer made of a light-absorbing resin member (B),
The cooling device, wherein the groove portion of the resin plate forms a coolant flow path. 2. The cooling device according to claim 1, wherein at least the peripheral edge portion of said resin plate and said metal plate are joined via said intermediate layer. 3. The cooling device according to claim 1, wherein the intermediate layer and the resin plate are welded together. The cooling device according to any one of claims 1 to 3, wherein the metal plate and the intermediate layer are joined by injection molding. 5. The cooling device according to any one of claims 1 to 4, wherein the metal plate has a fine concavo-convex structure formed on the surface of the joint with the intermediate layer. The light-absorbing resin member (B) contains a light-absorbing agent,
The cooling device according to any one of claims 1 to 5, wherein the content of the light absorbing agent in the light absorbing resin member (B) is 0.01% by mass or more and 5% by mass or less. The cooling device according to any one of claims 1 to 6, wherein outer peripheral ends of said resin plate and said metal plate are riveted or screwed. The metal plate according to any one of claims 1 to 7, wherein the metal plate is composed of at least one member selected from the group consisting of aluminum members, aluminum alloy members, copper members and copper alloy members. Cooling system. 9. The refrigerant flow channel formed in the resin plate according to any one of claims 1 to 8, wherein one end is connected to an injection pipe and the other end is connected to a discharge pipe. cooling system. 10. The cooling device according to any one of claims 1 to 9, wherein the cooling device is for cooling a battery block in which two or more battery cells are arranged on a flat surface so as to be in close contact with each other or to be adjacent to each other at a certain interval. or the cooling device according to claim 1. The cooling device according to any one of claims 1 to 9, wherein the cooling device is a cold plate for cooling electronic components. a battery block in which two or more battery cells are arranged on a flat surface so as to be in close contact with each other or adjacent to each other with a certain interval;
A cooling device according to any one of claims 1 to 10;
a case that houses the battery block;
with
A battery structure in which the battery block is arranged on the metal plate in the cooling device. 13. The battery structure according to claim 12, wherein said battery cells are lithium ion batteries.

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